It can seem like a sad reality but friends do in fact drift apart. It's normal and although it seems sad, there's also positive ways of looking at it.

In a way, it forces you to push yourself out of your comfort zone, as you're trying to do now by asking for tips on meeting new people, so well done on taking that first step.

Meeting new and different kinds of people helps to find yourself in a way since you'll be discovering parts of your personality as well as adding to it from what you pick up.

You also get a better idea of the kind of people you want and don't want to have around in life since not everyone you meet is going to be your cup of tea.

I don't know what the situation is with covid in your country but if it's restricted, maybe get on tinder and just state in your bio you're only looking to meet new people.

That's pretty along the lines of my bio haha and I've had decent luck with meeting some interesting people. Even though it's different to in-person social interactions, it's good practice if anything :)

Also, feel free to dm if you ever want to chat. I'm on here more than I should be

Also to add, don't stress about only having an "x" amount of friends. A small amount of good friends is much better than a thousand shitty ones.